The Merchant's Dormitory is a two-story structure on the south side of the castle. It was built into a hillside so that it is one-story high inside the castle and two-stories high outside. The upper floor, which held an elevated veranda on the outside, was likely a dwelling space for lower-ranking white workers. The semi-underground floor underneath was probably used as a storage area for European trade goods and bulk items purchased from African traders, such as animal hides, camwood, and ivory tusks.